Device for recovering lost underwater equipment

Abstract

The present invention relates to a device (10) for being attached onto underwater equipment comprising a socket (20) with fastening means (21) for securing the socket (20) to said underwater equipment, a watertight chamber (12) comprising air or gas so that a buoyance effect is achieved, and comprising attachment means (32) for releasably locking the watertight chamber to said socket, and a communication module (14) configured to transmit a signal comprising a geographical position of the device (10), wherein the socket (20) comprises one or more engagement means (22) for engaging with the attachment means (32), and where the attachment means (32) are configured to be operated between an engagement mode (42) where the watertight chamber (12) is locked to the socket (20) and a disengagement mode where the watertight chamber is unlocked from the socket, wherein the attachment means (32) comprises a pressure activated release mechanism (34) configured to operate the attachment means between the engagement mode (42) and the disengagement mode at a pre-determined pressure level of a surrounding body of water (1).

Description

[0001] [Device for recovering lost underwater equipment]

[0002] Field of the Invention

[0003] The present invention relates to the field of locating and recovering lost underwater equipment.

[0004] The lost underwater equipment is located and recovered by providing a device on the underwater equipment during deployment, the device can float to the surface and send a signal comprising the location of the device when the underwater equipment is lost underwater.

[0005] Background of the Invention

[0006] Underwater equipment such as fishing gear and in particular fishing nets made of nylon and / or other materials for both professional and recreational fishing are frequently lost at sea and not recovered. It is estimated that approximately 2% of all fishing gear is lost at sea. The fishing gear lost at sea will eventually accumulate in large sea debris islands; become entangled with marine creatures including birds; break down and decompose into microplastics and eventually be consumed by animals. The lost fishing gear made of plastic takes about 600 years to break down and decompose into microplastics. The fishing gear continues to catch fish by trapping marine creatures for a long time, this phenomenon is called ghost fishing.

[0007] Fishing gear including but not limited to fishing nets, trawls, dredges, seine nets, gill- nets, fishing cages and traps, lures, rope, line, hooks, harpoons, and spears will in the present disclosure be referred to as underwater equipment. The present invention is also directed at but not limited to underwater equipment including underwater vehicles, vessels, measurement equipment, ocean clean-up equipment, occupational equipment, oil and gas equipment, floating wave energy systems, etc. which may become lost at sea.

[0008] Underwater equipment is often lost because a buoy, which is intended to be the main item to identify the location of the underwater equipment, has been damaged or sunk. Rope connecting the underwater equipment to the buoy or the buoy itself may become damaged by collision with a vessel or other underwater equipment. The buoy may also be sunk if the underwater equipment is deposited or has drifted off to a deeper location than originally intended. In another aspect, the underwater equipment is connected by a rope to a fishing vessel, wherein the underwater equipment may be lost when the rope is damaged. When underwater equipment is lost, the process of recovery is difficult.

[0009] The current solutions for the owners of the underwater equipment to recover the lost underwater equipment is to use a dredge to dredge for the lost underwater equipment or to use remotely operated vehicles (RO Vs) or submarines to search for the lost underwater equipment. However, the problem inherent in both solutions is that the owners are searching blindly for the lost underwater equipment.

[0010] About 20-30% of all plastic pollution in the ocean comes from marine sources such as fishing nets, lines, ropes and abandoned vessels. Therefore, a solution is required to aid the recovery of lost underwater equipment and reduce ghost fishing and marine pollution and recover valuable equipment.

[0011] Object of the Invention

[0012] The objective of the invention is to provide a device attached to a rope and / or underwater equipment which can detect if a rope becomes detached from its buoy and / or vessel or if the rope and / or underwater equipment is submerged too deep relative to its intended use. When the device is subject to a change in pressure due to a change in depth, it will be released from the rope and / or underwater equipment, float to the surface, and send out a signal notifying the receiver of the location of the device, such that the receiver may recover the underwater equipment.

[0013] Description of the Invention

[0014] One objective of the invention is achieved by a device being attached to underwater equipment comprising:

[0015] - a socket with fastening means for securing the device to the underwater equipment,

[0016] - a watertight chamber comprising air or gas so that a buoyance effect is achieved and attachment means for releasably locking the watertight chamber to the socket, and - a communication module configured to transmit a signal comprising a geographical position of the device, wherein the socket comprises one or more engagement means for engaging with the attachment means, and where the attachment means are configured to be operated between an engagement mode where the watertight chamber is locked to the socket and a disengagement mode where the watertight chamber is unlocked from the socket, wherein the attachment means comprises a pressure activated release mechanism configured to operate the attachment means between the engagement mode and the disengagement mode at a pre-determined pressure level of a surrounding body of water.

[0017] The attachment means comprising a pressure activated release mechanism may alternatively be phrased as the attachment means comprises a pressure activated release mechanism configured to operate the attachment means in the engagement mode at a first distance below a water surface and in the disengagement mode at a pre-determined pressure level of a surrounding body of water at a second distance below the water surface, said second distance being at a lower depth than the first distance.

[0018] Releasably locking may be considered as being releasably fastening / fixing or mounting the watertight chamber to the socket.

[0019] In one aspect of the socket, the fastening means may be a clamp for securely fastening the socket to the underwater equipment. In another aspect the socket may be attached to the underwater equipment using epoxy, glue, or other adhesives. In another aspect the socket may be embedded into or onto the underwater equipment. One effect of releasably fastening the socket to the underwater equipment is that the socket may be attached at different places on the underwater equipment depending on the specific application. One further effect is that the device is easy to use on any underwater equipment.

[0020] The watertight chamber is configured with a housing which is sufficiently sealed so that the surrounding body of water is kept from entering the watertight chamber and the air or gas inside the watertight chamber is kept from exiting the watertight chamber. One effect of the watertight chamber is that it has a buoyancy effect sufficient for resurfacing the watertight chamber after the watertight chamber has been released from the socket. One further effect of the watertight chamber is that electronic components, e.g. the communication module, may be arranged inside the watertight chamber and are protected from the body of water outside the watertight container.

[0021] The communication module may alternatively be arranged outside the watertight chamber e.g. embedded in the housing comprising the watertight chamber.

[0022] The communication module may be configured to transmit a signal comprising a geographical position of the watertight chamber, housing and / or socket. A graphical position may e.g. be a latitude and longitude position code or a geocode system such as but not limited to Maidenhead Locator System or World Geographic Reference System.

[0023] The housing of the watertight chamber may be configured with a coating, paint and / or a surface material comprising a compound material adapted to sustain marine growth and fouling. The compound material may be but is not limited to copper-based paint or silicone-based coatings.

[0024] The pressure activated release mechanism operates the attachment means when a predetermined pressure level of the surrounding body of water is reached, i.e. during sinking of the device or the underwater equipment, the pre-determined pressure level is a pressure level below a normal pressure level of the normal operation of the underwater equipment which the device is attached to. As such the pre-determined pressure level may be adjusted for any specific application or for any specific placement of the device on the underwater equipment, such that the release mechanism is not erroneously or prematurely released. For example, during the normal operation of the underwater equipment the device is attached to a rope or fishing net and floats at a depth of 5-10 meters below the surface, when the device is further submerged to 15 meters of depth the pre-determined pressure level is reached and the pressure activated release mechanism operates the attachment means into the disengagement mode so that the watertight chamber floats to the surface. These depth levels are only examples of the principle of the device, in actual use the depth of normal operation may span a wide range of depths and the distance between the depth of normal operation and the depth where the device is released is entirely configured by the user of the device prior to submersion of the underwater equipment. The pressure sensitive release mechanism and / or attachment means can be configured to activate the communication device to start transmission of the signal comprising the geographical position of the device. In another aspect the communication device may await transmission of the signal until the watertight chamber has resurfaced. One effect hereby achieved is that power consumption of the device is reduced and less battery capacity is required, thus prolonging the time between maintenance and / or replacement of a battery and reducing the cost of the device. In another aspect a saltwater switch is provided, when the device is submerged the saltwater switch keeps the communication device in an offline state and when surfaced above water the communication device is activated to start transmission of the signals.

[0025] One advantageous effect of providing the communication module is that the owner of the underwater equipment or other personnel can nearly instantly receive information on underwater equipment becoming lost, thus making recovery of the lost underwater equipment much quicker, increasing the chance of recovery and decreasing the risk that the underwater equipment can damage marine life and underwater plants.

[0026] In one embodiment of the device, the device comprises a spool with a line wound around the spool, the line is at one end attached to the spool and at an opposite end attached to the watertight chamber or the socket.

[0027] When the watertight chamber is released from the socket due to e.g. the device being sunk below a normal depth, the line is used to recover the socket and / or the underwater equipment.

[0028] In case the line itself is not sufficiently strong to recover the underwater equipment, the line may advantageously be used for tracing a path to the socket and / or underwater equipment from the watertight chamber for a rope with a higher tensile force. The tracing may be accomplished by connecting e.g. a grappling hook and an external rope to the line so the grappling hook follows the line towards the underwater equipment. Once the grappling hook has reached the underwater equipment it can be attached to the underwater equipment and the underwater equipment can be recovered by pulling the rope and the grappling hook to the surface. The line may be of a synthetic material such as but not limited to an aramid rope or nylon rope and may be used to recover the underwater equipment without an additional grappling hook and rope.

[0029] In one embodiment of the device, the engagement means comprises one or more pins for engaging with apertures arranged in the attachment means.

[0030] The attachment means may be configured with one or more apertures forming a female receptacle for engaging and mating with the one or more pins of the engagement means forming a male connector. The socket comprises a slidable rod, wherein the pins are arranged on the slidable rod. The slidable rod is configured to slide in a direction causing the pins to engage and disengage from the attachment means. The slidable rod comprises a biased spring so that it forces the pins to disengage from the attachment means when released. The attachment means comprises a locking pin for locking the slidable rod in a position where the pins are engaged with the apertures, i.e. the engagement mode. When the pressure activated release mechanism operates the attachment means into the disengagement mode, the locking pin is unlocked from the slidable rod, so that the biased spring pushes the slidable rod in the direction causing the pins to disengage from the attachment means.

[0031] The slidable rod may also be configured to rotate around a central axis parallel to the slidable rod in order to unlock the pin from the attachment means.

[0032] In another aspect of the attachment means and engagement means, the attachment means may comprise one or more pins and the engagement means may comprise one or more apertures.

[0033] In one embodiment of the device, the pressure activated release mechanism comprises a pressure sensitive membrane with a surface configured to be in contact with the surrounding body of water and connected to a spring with a spring force, the pressure sensitive membrane is configured to push and / or pull the spring at the pre-determined pressure level, so that the pressure activated release mechanism operates the attachment means into the disengagement mode. The pressure sensitive membrane may be arranged with a part of its surface in contact with the surrounding body of water, such that when the pressure of the surrounding body of water changes, the pressure sensitive membrane is pulled and / or pushed in a direction approximately perpendicular to the surface of the membrane, i.e. inwards and / or outwards.

[0034] The pressure sensitive membrane and / or the spring may be chosen with specific properties so that the operation of the attachment means occurs at a precise pressure level and / or the pre-determined pressure level, thus enabling the device to be designed and / or reconfigured for a specific application.

[0035] In one embodiment of the pressure sensitive membrane, the opposite side of the surface configured to be in contact with the surrounding body of water faces a sealed volume which may comprise air, gas, a liquid or a combination thereof. The gas, liquid or combination thereof in the sealed volume may be any compressible or expandable mixture so that the pressure sensitive membrane is configured to push and / or pull the spring at the pre-determined pressure level.

[0036] In one embodiment of the device, the device comprises a battery, an electronic pressure sensor and / or an electronic release mechanism, wherein the electronic pressure sensor can detect the pressure of the surrounding body of water and instruct the electronic release mechanism to operate the attachment means into the disengagement mode when the pressure of the surrounding body of water is at the pre-determined pressure level.

[0037] In one aspect the electronic pressure sensor may be configured to measure the pressure of the surrounding body of water and output the pressure level as an analogue or digital electrical signal. In another aspect the pressure sensor may be configured to output an instruction, i.e. a binary signal, directing the electronic release mechanism to operate the attachment means into the engagement mode or the disengagement mode. The electronic release mechanism may be configured to receive a signal comprising a pressure level and / or an instruction as input signal. In another aspect, the electrical signal of the pressure level may be transmitted to a general-purpose processor and the processor is configured to output an instruction directing the electronic release mechanism to operate between the engagement mode and the disengagement mode.

[0038] In one aspect of the electronic pressure sensor, the electronic pressure sensor may be placed inside the watertight chamber, and comprises a measurement diaphragm, wherein a first side of the measurement diaphragm is in contact with the surrounding body of water through a pressure port, a second side of the measurement diaphragm opposite the first side is in contact with a reference chamber and a sensor beam is arranged on the second side and is configured for measuring an electrical signal. The reference chamber is dimensioned to ensure correct pressure measurement.

[0039] In one aspect of the electronic release mechanism, the electronic release mechanism may be one or more electromagnets arranged in the watertight container and configured to fasten a magnetic part of the socket to the watertight container in the engagement mode. When the electronic release mechanism receives an input instructing to engage the disengagement mode, the electromagnets release the magnetic part of the socket.

[0040] In another aspect of the electronic release mechanism, the electronic release mechanism may be a linear actuator or a gripping hand configured to engage and lock together with the socket. The linear actuator can lock with the slidable rod similar to the locking pin as disclosed herein.

[0041] The battery, electronic release mechanism and / or processors may also be arranged inside the watertight chamber to protect the electronic equipment from deteriorating or shorting out due to conditions of the surrounding body of water.

[0042] In one embodiment of the device, the communication module comprises one or more receiver modules configured for receiving a global positioning signal and / or a transmitter module configured for transmitting one or more signals, wherein the signals comprise information of the geographical position of the device.

[0043] The signals transmitted and received by the communication module may be electrical signals, digital communication signals, analogue signals, electromagnetic waves and / or a combination thereof. The communication module may comprise one or more antennas for receiving and / or transmitting signals. The antennas may be arranged inside the watertight chamber, outside the watertight chamber or embedded in a surface of the watertight chamber. One effect of arranging the antenna on the outside of the watertight chamber may be that a better signal transmission and reception is achieved. The antennas may also be configured with a gain and a directivity suitable for reception and transmission of signals to satellites, beacons and / or antenna towers.

[0044] The communication module may comprise one or more receiver modules and one or more transmitter modules with circuitry configured for receiving a global positioning signal (GPS) and transmitting one or more signals, respectively.

[0045] The global positioning signal may comprise but is not limited to one or more signals from a global navigation satellite systems (GNSS), BeiDou Navigation Satellite System (BDS), Galileo, Globalnaya Navigazionnaya Sputnikovaya Sistema (GLONASS), Indian Regional Navigation Satellite System (IRNSS), Navigation Indian Constellation (NavIC), Argos satellite system and / or Quasi-Zenith Satellite System (QZSS). In another aspect a positioning signal comprises one or more signals from an Automatic Identification System (AIS)

[0046] The receiver modules may be configured for receiving a multi -band signal, i.e. more than one signals from one or more satellite systems.

[0047] The transmitter module may also be configured for transmitting the signal over a communication network such as but not limited to Global System for Mobile Communications (GSM), AIS, general-purpose radio communication (very low frequency band to extremely high frequency band) or satellite communication.

[0048] The transmitter module may further be configured for transmitting a low frequency band signal, e.g. 406 MHz through a EPIRB, PLB or ELT protocol. The low frequency signal may be used for alerting an external communication receiver of the location of the transmitter through one or more satellites. In one embodiment of the device, the transmitter module is configured to communicate with an external communication receiver.

[0049] The external communication receiver may be configured for receiving the electrical signal over a communication network such as but not limited to GSM, AIS, general- purpose radio communication, or satellite communication. The external communication receiver may comprise a display configured for displaying the geographical position of the device received from the transmitter module of the device, or it may comprise a seven-segment display or similar for displaying the received information of the geographical position as a latitude and longitude position code, in e.g. decimal degrees.

[0050] The external communication receiver may also be configured for storing an initial geographical position of the device, wherein the initial position is a position where the underwater equipment and the device were initially submerged into the body of water.

[0051] In one embodiment of the device, the device comprises one or more light emitting diodes for visually marking the position of the device.

[0052] The one or more light emitting diodes (LEDs) may be arranged on the surface of the watertight chamber. In another aspect, one or more LEDs may also be arranged on the socket. The one or more LEDs may be a high intensity brightness LED and / or multicolour LED comprising two or more different colours of light suitable for being combined and mixed to emit a variety of different colours of light. The colours of light may be but is not limited to red, green, blue, white, amber and / or a mix. The LED may also be an infrared LED suitable for being detected by night vision goggles, cameras or infrared sensors.

[0053] The LEDs may be configured to start emitting light when the watertight chamber is released from the socket or when the watertight chamber has resurfaced. As such, the LEDs may be controlled by the pressure activated release mechanism or the processor.

[0054] The one or more LEDs may be configured to emit light constantly and / or emit a specific pattern such as a SOS morse code. In another aspect, the LEDs may be configured to blink or flicker with a specific frequency of e.g., 10 Hz, 5 Hz, 1 Hz, 0.5 Hz, 0.1 Hz, 0.01 Hz, less frequent or anywhere in-between. The LEDs may be configured to emit different patterns of light. One advantage of the emitting different patterns of light is that the LEDs may become more visible and the energy consumption of the LEDs is reduced.

[0055] In an embodiment where more than one LED are provided, one or more LEDs may be configured to have a synchronized flash and / or colour of light.

[0056] In one embodiment of the device, the device is configured to operate below a water surface at a pressure level of the surrounding body of water in the range of 1 to 50 bar, preferably in the range of 1 to 25 bar and even more preferably in the range of 1 to 10 bar.

[0057] With 1 bar is meant the pressure at the water surface at sea or of a lake. Thus 1 bar here may be 0.8-1.1 bar considering the geographical height where the device is used e.g. in mountain lakes.

[0058] The watertight chamber may comprise a housing made of plastic and / or metal such as stainless steel and is configured to be watertight at a pressure level of the surrounding body of water equal to at least 50 bar.

[0059] The device may be configured for an exemplary application where normal operation is at a depth where the pressure level of the surrounding body of water is equal to a range between 1 and 5 bar and where the pre-determined pressure level is 8 bar for the pressure activated release mechanism to operate the attachment means between the engagement mode and the disengagement mode. The device may be configured for any application wherein the normal operation is a range between 1 and 50 bar and the pre-determined pressure level is a pressure level higher than that range.

[0060] In a further embodiment of the device, the device is powered by wave energy.

[0061] One effect of the device being powered by wave energy may be that the device may be deployed for an unlimited time frame and maintenance is required less often. Another effect is that the device can emit light through LEDs, receive and / or transmit signals for a longer period of time, because there is no limited battery capacity.

[0062] One further objective of the invention is also achieved by a kit comprising one or more ropes, underwater equipment, one or more buoys or a vessel and one or more devices according to any one of the herein disclosed embodiments, wherein the underwater equipment is arranged on a first end of the rope, the buoy or the vessel is arranged on a second end of the rope, and the one or more devices are attached to the rope at one or more positions along the rope and / or to the underwater equipment.

[0063] At least two devices may be attached to the rope and / or underwater equipment for redundancy.

[0064] One advantage of attaching multiple devices to the rope and / or underwater equipment, may be that if only a single device is placed on the rope at a first location and the rope breaks at a location between the first location and the first end of the rope, the single device will not activate when a lower end of the rope and / or underwater equipment is lost, because the single device is still attached to an upper end of the rope and the buoy.

[0065] One further advantageous effect of providing a kit for the device may be that any one person may combine the underwater equipment comprised in the kit suitable for e.g. catching fish or any other application and attach one or more devices onto the rope or the underwater equipment so that if the underwater equipment is lost by becoming detached from one or more buoys or vessels, the underwater equipment can be recovered by receiving a signal from the communication module and the geographical position of the watertight chamber and / or the devices.

[0066] The invention is also directed to a use of the device according to any one of the herein disclosed embodiments attached to underwater equipment and an external communication receiver, when the device is submerged to a pressure level of the surrounding body of water equal to the pre-determined pressure level the pressure activated release mechanism operates the attachment means into the disengagement mode so that the device is unlocked from the underwater equipment and the communication module transmits a signal, so that the communication receiver receives the geographical position of the device.

[0067] The invention is also directed to a use of the device according to any one of the herein disclosed embodiments, wherein an external communication receiver comprises a software application for receiving notification of events and / or location of the device and / or the watertight chamber.

[0068] Events may cover non-intended use e.g. if the device arrives at the water surface without the pressure activated release mechanism being activated.

[0069] Description of the Drawing

[0070] Figure 1 illustrates one embodiment of the device.

[0071] Figure 2a illustrates one further embodiment of the device.

[0072] Figure 2b illustrates the one further embodiment of the device operated in the disengagement mode.

[0073] Figure 3 a illustrates one further embodiment of the device.

[0074] Figure 3b illustrates one further embodiment of the device.

[0075] Figure 4 illustrates one embodiment of the device with a spool and line.

[0076] Figure 5 illustrates one embodiment of the kit.

[0077] Figure 6a illustrates one embodiment of the device attached to the underwater equipment.

[0078] Figure 6b illustrates one embodiment of the device operated in the disengagement mode.

[0079] Detailed Description of the Invention

[0080] Figure 1 illustrates one embodiment of a device 10 surrounded by a body of water 1 comprising a watertight chamber 12 with a buoyance effect, a socket 20 with fastening means 21 for securing the device to underwater equipment. The fastening means 21 may be a clamping device as illustrated for clamping onto a round object such as a rope or fishing line. The fastening means 21 may be configured as any other clamping devices such as a claw clamp, or it may be fastened onto the underwater equipment with screws, bolts and nuts, glue and / or epoxy. In another aspect, the socket is embedded into a surface of the underwater equipment.

[0081] The socket 20 comprises a number of engagement means 22 configured for engaging with a number of attachment means 32 arranged on the watertight chamber 12. In this illustration, the attachment means 32 are operated in an engagement mode 42, wherein the attachment means 32 are engaged with the engagement means 22 so that the watertight chamber 12 is locked to the socket 20. The attachment means further comprises a pressure activated release mechanism 34 configured to operate the attachment means between the engagement mode 42 and a disengagement mode 44 at a pre-determined pressure level of the surrounding body of water. When the attachment means 32 are operated in the disengagement mode 44, the watertight chamber 12 is unlocked from the socket 20. When the watertight chamber 12 is unlocked from the socket 20, the buoyance effect will force the watertight chamber 12 to surface the body of water.

[0082] Figure 2a illustrates one further embodiment of the device 10, wherein the engagement means 22 comprises one or more pins 23 configured for engaging with one or more apertures 33 arranged in the attachment means 32. The pins 23 are arranged on a slidable rod 24 which is configured to slide in a first direction where the pins 23 are disengaged from the apertures 33 and in a second direction where the pins 23 are engaged into the apertures 33, i.e. the disengagement mode 44 and the engagement mode 42, respectively. The slidable rod further comprises a biased spring 28 configured for forcing the pins 23 to disengage from the apertures 33 when the attachment means are operated into the disengagement mode 44. In another aspect of the pins 23, the pins 23 individually comprises biasing springs and are configured to slide between the first direction and the second direction.

[0083] Figure 2b illustrates a further embodiment of the device 10, the pressure activated release mechanism 34 comprises a pressure sensitive membrane 36 with a surface configured to be in contact with the surrounding body of water 1 and connected to a spring 38 with a spring force. When a pressure level of the surrounding body of water 1 changes, the pressure sensitive membrane 36 is configured to push and / or pull in a direction perpendicular to the surface of the pressure sensitive membrane 36. As the pressure sensitive membrane 36 is pushed and / or pulled, the spring 38 is also pushed and / or pulled at the pre-determined pressure level. When the spring 38 is pushed together, the attachment means 32 is operated into the disengagement mode 44 as illustrated in the figure. Consequently, the attachment means 32 are disengaged from the engagement means 22 and the watertight chamber 12 is unlocked from the socket 20.

[0084] The spring 38 may be configured with a specific spring force in order to set the predetermined pressure level. Similarly, the pressure sensitive membrane 36 may be configured with a specific stiffness in order to set the pre-determined pressure level for a given application.

[0085] Figure 3a illustrates one further embodiment of the device 10, wherein the device 10 comprises an electronic pressure sensor 56, a battery 51, and / or an electronic release mechanism 52. The electronic release mechanism 52 may comprise one or more electromagnets 53 configured to be activated and fasten with a magnetic object 54 arranged on the socket 20 or to be deactivated and detach from the magnetic object 54. The electronic release mechanism 52 is instructed to activate and / or deactivate by the electronic pressure sensor 56 and / or a general-purpose processor 50 arranged in the watertight chamber 12. The general-purpose processor 50 may be configured to receive inputs from the electronic pressure sensor 56 comprising a pressure level of the surrounding body of water 1 and to transmit output comprising one or more instructions to the electronic release mechanism 52 and / or the communication module 14. In a further embodiment of the device 10, the watertight chamber 12 comprises one or more light emitting diodes (16) arranged in a surface of the watertight chamber 12 facing the surrounding body of water.

[0086] Figure 3b illustrates one further embodiment of the device 10, wherein the electronic release mechanism 52 is configured as a linear actuator 55 for being controlled by the electronic pressure sensor 56 and / or the general-purpose processor 50. In this embodiment the linear actuator 55 is configured to engage with engagement means 22 arranged on the socket 20. In this illustration the linear actuator 55 is engaged in the engagement mode 42, and it may be disengaged into the disengagement mode 44 by retracting and / or rotating an extension tube of the linear actuator.

[0087] Figure 4 illustrates one embodiment of the device 10 wherein the socket 20 comprises a spool 70 with a line 72 wound around the spool 70. The spool is arranged in a winch 78 configured to wind and unwind the line 72. A first end of the line 70 may be fastened to the spool 70 or the socket 20, and an opposite end 74 may be attached to an eyelet 76 or similar holding means arranged on the surface of the watertight chamber 12.

[0088] Figure 5 illustrates one embodiment of a kit comprising a rope 5, underwater equipment 4, a buoy 7 and a device 10 attached to the rope 5 with fastening means 21. The illustration shows a first scenario of normal operation of the device 10 attached to underwater equipment 4, e.g. fishing gear 6. The underwater equipment 4 is arranged on a first end 8 of the rope, the underwater equipment 4 may be a fishing net as illustrated or it may be any other underwater equipment as defined herein. The buoy 7 is arranged on a second end 9 of the rope 5 opposite the first end 8, the buoy 7 may also be any other floating vessel such as a ship or boat.

[0089] The device 10 is preferably attached to the rope 5 at a position on the rope 5 at a sufficient depth below a water surface 2 of the body of water 1, so that the device 10 cannot collide with or become damaged by other vessels. In this embodiment, the device is configured to float along in a depth range indicated by the first distance 60. As such the pressure activated release mechanism 34 is configured with a pre-determined pressure level which appears below the first distance 60. Figure 6a illustrates one embodiment of the device 10 attached to underwater equipment 4 and illustrates a second scenario of underwater equipment 4 being lost below the water surface 2. The buoy 7 has been submerged below the water surface 2 and the device 10 is submerged to a lower depth range than the first distance 60 as indicated by the second distance 62. As the device 10 is submerged to a second distance 62 wherein the pressure reaches or exceeds the pre-determined pressure level, the pressure activated release mechanism 34 operates the attachment means 32 into the disengagement mode 44 so that the watertight chamber 12 is unlocked from the socket 20 and the underwater equipment 4.

[0090] Figure 6b illustrates one embodiment of the device 10 operated in the disengagement mode 44 and a third scenario of the device 10 being used to signal a geographical location of underwater equipment 4 lost below the water surface 2. As the device 10 has been submerged to a depth where the pressure level of the surrounding body of water 1 is at or above the pre-determined pressure level, the watertight chamber 12 is released from the socket 20 and will float to the water surface 2. As the watertight chamber 12 is released and / or resurfaces the communication module 14 will commence reception of one or more global positioning signals and transmission of a geographical position of the watertight chamber 12. In a further embodiment, one or more light emitting diodes 16 may also be activated to visually illuminate the watertight chamber 12 as the watertight chamber 12 is released and / or resurfaces. In a further embodiment, as the watertight chamber 12 floats to the water surface 2, the line 72 is unwound from the spool 70 and the line provides a direct link between the watertight chamber 12 and the socket 20, the underwater equipment 4, rope 5 and buoy 7 such that all lost equipment may be recovered after locating the watertight chamber 12.

[0091] In another scenario where the rope 5 is cut between the buoy 7 and the socket 20 and the underwater equipment 4 and rope 5 are submerged to a depth where the pressure level of the surrounding body of water 1 is at or above the pre-determined pressure level, the watertight container 12 will float to the surface and provide a means of recovery for the underwater equipment 4 and the rope 5.

Claims

CLAIMS1. A device (10) for being attached onto underwater equipment (4) comprising:- a socket (20) with fastening means (21) for securing the socket (20) to said underwater equipment,- a watertight chamber (12) comprising air or gas so that a buoyance effect is achieved, and comprising attachment means (32) for releasably locking the watertight chamber to said socket, and- a communication module (14) configured to transmit a signal comprising a geographical position of the device (10), wherein the socket (20) comprises one or more engagement means (22) for engaging with the attachment means (32), and where the attachment means (32) are configured to be operated between an engagement mode (42) where the watertight chamber (12) is locked to the socket (20) and a disengagement mode (44) where the watertight chamber is unlocked from the socket, wherein the attachment means (32) comprises a pressure activated release mechanism (34) configured to operate the attachment means in the engagement mode (42) at a first distance (60) below a water surface (2) and in the disengagement mode (44) at a predetermined pressure level of a surrounding body of water (1) at a second distance (62) below the water surface (2), said second distance being at a lower depth than the first distance.

2. The device according to claim 1, wherein the device (10) comprises a spool (70) with a line (72) wound around the spool, said line (72) is at one end attached to the spool and at an opposite end (74) attached to the watertight chamber (12) or the socket (20).

3. The device according to claim 1 or 2, wherein the engagement means (22) comprises one or more pins (23) for engaging with apertures (33) arranged in the attachment means (32).

4. The device (10) according to any one of the preceding claims, wherein the pressure activated release mechanism (34) comprises a pressure sensitive membrane (36) with a surface configured to be in contact with the surrounding body of water (1) and connected to a spring (38) with a spring force, the pressure sensitive membrane is configured to push and / or pull the spring at the pre-determined pressure level, so that thepressure activated release mechanism (34) operates the attachment means (32) into the disengagement mode (44).

5. The device (10) according to any one of the preceding claims, comprising a battery (51), an electronic pressure sensor (56) and / or an electronic release mechanism (52), wherein the electronic pressure sensor can detect the pressure of the surrounding body of water (1) and instruct the electronic release mechanism to operate the attachment means (32) into the disengagement mode (44) when the pressure of the surrounding body of water is at the pre-determined pressure level.

6. The device (10) according to any one of the preceding claims, wherein the communication module (14) comprises one or more receiver modules configured for receiving a global positioning signal and / or a transmitter module configured for transmitting one or more signals, wherein the signals comprise information of the geographical position of the device.

7. The device (10) according to claim 6, wherein the transmitter module is configured to communicate with an external communication receiver.

8. The device (10) according to any one of the preceding claims comprising one or more light emitting diodes (16) for visually marking the position of the device.

9. The device (10) according to any one of the preceding claims, wherein the device is configured to operate below a water surface (2) at a pressure level of the surrounding body of water (1) in the range of 1 to 50 bar, preferably in the range of 1 to 25 bar and even more preferably in the range of 1 to 10 bar.

10. The device (10) according to any one of the preceding claims, wherein the device is powered by wave energy.

11. A kit comprising one or more ropes (5), underwater equipment (4), one or more buoys (7) or a vessel and one or more devices (10) according to any one of claim 1 to 10, wherein the underwater equipment is arranged on a first end (8) of the rope, the buoy or the vessel is arranged on a second end (9) of the rope, and the one or moredevices (10) are attached to the rope at one or more positions along the rope and / or to the underwater equipment.

12. Use of the device (10) according to any one of the preceding claims attached to underwater equipment (4) and an external communication receiver, when the device is submerged to a pressure level of the surrounding body of water (1) equal to the predetermined pressure level the pressure activated release mechanism (34) operates the attachment means (32) into the disengagement mode (44) so that the device (10) is unlocked from the underwater equipment (4) and the communication module (14) trans- mits a signal, so that the communication receiver receives the geographical position of the device.

13. Use of the device (10) according to any one of the preceding claims, wherein an external communication receiver comprises a software application for receiving notifi- cation of events and / or location of the device (10) and / or the watertight chamber (12).

Images